Cal. Gov. Code § 12061
As soon as practicable after the effective date of this article, and thereafter as soon as practicable after election and qualification to office, the Governor shall appoint and designate by filing with the Secretary of State the names of at least four and not more than seven citizens qualified to become candidates for the office to succeed, in the order specified, to the office of Governor in the event of disaster. Any such appointee may be replaced by the Governor at any time and for any reason.
In making appointments the Governor shall give consideration to places of residence and employment of the appointees and shall appoint from different parts of the State so that there shall be the greatest probability of survival in a disaster.
The names of the persons designated pursuant to this section shall be submitted to, and shall be subject to confirmation by, the Senate as soon as possible after that designation is made.
Each person appointed as provided in this section shall take the oath of office and shall deliver to the Secretary of State within 30 days after appointment a written declaration under oath that the appointee accepts the appointment and that the appointee will faithfully perform the obligations imposed upon the appointee thereby and shall thereupon be designated Disaster Acting Governor.
Ca. Gov. Code § 12061